Bumper safety joint



Jall- 1960 A. v. SEGELHORST BUMPER SAFETY JOINT Filed Oct. 10, 1955 dwarf.

BUMPER SAFETY JOINT August V. Segelhorst, Corona Del Mar,'-Calif., assignor to S. R. Bowen C0., Santa Fe Springs, Calif., a corporation of California Application October 10, 1955, Serial No. 539,441

7 Claims. (Cl. 255-28) This invention relates to a safety joint, particularly for oil wells, whereby the drilling string or drill pipe is connected to the tool, such as a bit, by means of a safety joint/which can be uncoupled in event that the tool becomes stuck in the well so that the drilling string can be removed and retrieved leaving the tool in the hole, if necessary. I

An object of my invention is to provide a novel safety joint which permits the drilling string to be uncoupled from the tool.

Another object of my invention is to provide a novel means of pressing the driving surfaces'of the mandrel portion of the tool against driving lugs on the tubular body portion of the tool to prevent-vibration or chattering between these parts while the tool is operating.

Another object of my invention is to provide a novel means of coupling the mandrel and the tubular body portions of the tool through the means of H-shaped slots inthe mandrel and lugs on the tubular body, these parts being engageable and disengageable by the operator to permit release of the drilling stringfrom the tool, as might be necessary.

Another object of my invention is to provide a novel sleeve construction within the tubular body which acts as a locking member to prevent accidental disengagement of the mandrel and the tubular body.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims.

In the drawing:

Figure 1 is a longitudinal section view of my safety iOll'llI.

'Figure 2 is an enlarged vertical sectional'view of the coupling means between the mandrel and the tubular body.

I Figure 3 is a sectional view taken on line 3-3 of Fig. 1.

ice

The mandrel .2 is formed with a plurality of verticalslots 8 in the wall thereof, which are termed H-shaped slots, and these slots also each include a horizontal opening 9 which extends into a vertical slot 10. The slots.

10 are open at the bottom and closed at the top andthe function of these various slots will be subsequentlydescribed; that is, the slots are closed at the upper endby a wall. The tubular body or sleeve 4 has a plurality of inwardly projecting lugs 11 provided therein and these lugs are substantially the same length as the horizontal openings 9. They are also substantially the same-width as the vertical slots 8. When the mandrel 2 enters the tubular body 4 the. lugs 11 will first enter the verticalslots .10 and the top of the lugs 11 strike the top of'the slots 10, as indicated at 10, and thus will align all of the lugs with the horizontal slots 9. Rotation of the mandrel 2, in a clockwise direction as viewed from the top, will face and are being lifted slightly sufficient to move the lugs 11 as described. Also the weight of the tubular.

body 4 will tend to move the lugs 11 to the bottom of the slots 8. The mandrel 2 is reduced in diameter below. the slots 8, as shown at 12, and a plurality of vertically positioned keys 13 project outwardly from this portion of the mandrel. These keys are in axial alignment with the slots 8. The keys 13 are all formed with a tapered surface 14 on the bottom thereof and these surfaces cam the mandrel 2 clockwise, as viewed from the top, to press the lugs 11 against the sides of the vertical slots 8 toprevent chatter or vibration betweenthe mandrel 2 and the tubular body 4. This camming action is achieved by coaction with the locking sleeve as follows. A locking sleeve 15 is slidably and rotatably mounted withinthe tubular body 4- and surrounds the reduced portion Figure 4 is a sectional view taken on line44 of Fig. l and showing the keys 13 at the upper edge of the keyways 17.

Figure 5 is a sectional view taken ou line 55 of Fig. l

Figure 6 is a side elevation of the locking sleeve.

Figure 7 is a fragmentary side elevation of the mandrel as a bit, scraper,'fishing tool, etc. -The mandrel 2 is I tubular in shape, that is, it has a central vertical hole or passage extending therethrough through which the circulating fluid can pass. a

p The means of detachably connecting the mandrel 2 and the tubular body'4 is as follows:'

12 of the mandrel 2. A spring 16 within the tubular body 4 presses against the bottom of the lock sleeve 15 and rests at its lower end on top of the subS. This spring yieldably urges the lock sleeve 15 upwardly into engagement with the cam surfaces 14 of the keys 13. The lock sleeve 15 is provided with vertical keyways 17 into which the keys 13 move in one position of the mandrel 2.' Cam slots 18 are also formed in the sleeve 15 and extend into each of the vertical keyways 17. Pins 19 project inwardly from the tubular body 4 and enter one of the slots 18. The lower portions of the slots 18 are cut on a taper or inclined cam surface to permit a limited vertical movement of the sleeve 15 before the pins 19 enter the horizontal portion of the slots 18. This vertical movement of the sleeve 15 is accomplished due ,to the fact that the cam surfaces 14 of the keys 13 are engaged by the flared upper surfaces 20 of the slots 17, which flared surfaces engage the cam surfaces 14, thus tending to rotate the mandrel 2 clockwise as viewed from the top, because of the upward pressure of the spring 16 against the bottom of the sleeve 15. This presses the sides of the lugs 11 against the sides of the vertical slots 8 to prevent vibration or chattering between these parts. The lower edges of the lugs 11, as well as the lower surfaces of the slots 3, are tapered to provide taper engaging surfaces which Will more effectively prevent vibration or chattering between these parts. Also as the keys 13 move downwardly'in the vertical slots 17, thus tending to rotate the sleeve 15 counterclockwise as viewed from the top,

the earns 18 will be engaged by the pins 19, thus causing the sleeve 15 to be pushed downwardly against the compression of the spring 16 until the pins 19 reach the horizontal portion of the slots 18. The downward movement of the keys 13 is performed when the fish is stuck and it is desired to retrieve the inner portion of the tool.

Patented Jan. 5, 1960 When the pins 19 are in the horizontal portion of the slots 18 the drill string 1 with the mandrel 2 is rotated counterclockwise, as viewed from the top, and this movement of the mandrel does two things; first, the sleeve 15 is rotated relative to the pins 19 until the pins reach the dotted line position in Figure 2, that is, parallel with the corresponding slot 17. At the same time the lugs 11 are moved through the horizontal openings 9 to align them with the vertical slots it). The slight downward movement of the mandrel 2 during this rotation of the sleeve 15 positions the lugs 11 opposite the horizontal portion 9 of the slots. Further rotation of the mandrel will then move the lugs ll into the vertical slots 10. The parts are now in a position so that the mandrel 2 can be pulled upwardly out of the tubular body 4. The parts are assembled in the same manner, except in reverse, from that described above. The shoulder 21 on the bottom of the upper part of the mandrel 2 acts as a stop to engage the top of the sleeve 15 in one position of the parts.

A wash pipe 22 extends upwardly through the sub 5 and the upper end of the wash pipe enters the bottom of the reduced portion 12 of the mandrel 2. A floating seal or ring 23 surrounds the wash pipe 22 and packs off against this pipe with suitable packing, and also engages the inner wall of the sub 5 and also packs off against this inner wall. The stud 3d screws into the sub 5 and serves as a stop to prevent further upward movement of the packing ring or floater 23. The lower end of the wash pipe 22 is fitted in the pin 6, as shown.

In peralz'0n.-The sub is threaded onto the tool 7 and the spring 16 engages the bottom of the lock sleeve 15, pressing this lock sleeve upwardly to hold the pins 19 in the bottom of the slots 18. The mandrel 2 is now inserted into the top of the tubular body 4 in a position so that the lugs 11 will enter the vertical slots the reduced portion 12 being of a diameter to pass the lugs 11. Rotation to the right, or clockwise as viewed from the top, will move the lugs 11 into the vertical portion 3 of the slots in the mandrel 2. During this latter positioning of the mandrel 2 the keys 13 have first entered the keyways 17 and the pressure of the spring 16 has tended to cam or rotate the mandrel 2 in a clockwise direction, as viewed from the top. When the mandrel 2 is moved upwardly or picked up the lugs 11 will move to the bottom of the slots 3, and at the same time the keys 13 will move to the position shown in Figure l in which the sleeve is engaging and pressing against the cam sur faces 14. Compression of the spring in will now hold the parts in this position. When it is desired to release the mandrel 2 from the tubular body 4 and with the tool 7 stuck in the hole and, therefore, nonrotatably held, the following movements are performed: The first movement is to press the mandrel 2 downwardly. The cam surfaces 14 on the keys 13 now rotate the sleeve 15 counterclockwise, as viewed from the top, camming the sleeve downwardly due to the cam surfaces 20, and also moving the pins 19 into the horizontal portion of the slots 18. These keys 13 have now moved into the keyways 17, as shown in Figure 2. Also the pins 19 have moved into the cam slots 18 since the lock sleeve 15 can rotate within the tubular body 4. The lugs 11 are now substantially at the top of the vertical slots 8. Counterclockwise rotation, as viewed from the top, simultaneous with a small upward movement of the drill pipe 1 will cause the lugs 11 to move through the slots into the vertical slots 11), and in this position the mandrel 2 is free to be pulled upwardly out of the tubular body 4, thus retrieving the drill pipe and leaving the tubular body 4, the sub 5, and the tool 7 attached thereto in the hole.

My safety joint is usually positioned immediately above the bit; consequently, during the drillin operation the bit, safety joint and a portion of the drill pipe above the safety joint will be under compression. However, when the bit is lifted off of bottom, or if the bit is stuck in the bore and an upward strain is taken on the drill pipe, the.

pipe and safety joint will be in tension. During the separation of the safety joint and the subsequent removal of the drill pipe, the drill pipe and the mandrel 2 will be in tension. During drilling operation of the tool the lugs 11 will be within the slots 8 and, therefore, these lugs would be permitted only a limited vertical movement within these slots. As long as the mandrel 2 has a clockwise torque thereon (as viewed from the top) then the lugs 11 will remain in the slots 8 and the tool cannot be disconnected. It is only when the tool is intentionally re leased, that is, by lifting upwardly on the drill pipe and rotating the drill pipe and mandrel 2 counterclockwise, as viewed from the top, that the lugs will enter the slot 10. An indication of the position of the lugs 11 is very evident at the surface because in these operations the drill pipe is moved by hand through the medium of a long pipe wrench and, consequently, the operator can readily feel when the lugs come to a stop, that is, when they strike either the side of the slot ill or the slots 8.

Having described my invention, I claim:

1. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots therein designated as first and second slots, and a horizontal slot extending between the vertical slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slot, a lock sleeve in the tubular body, a key on the mandrel, a cam surface on the key, said lock sleeve having a slot therein to receive said key, said slot being engageable by the cam surface on the key, means yieldably pressing the lock sleeve against the key to rotatably urge the mandrel in the tubular body and press said lugs and a side of the second vertical slots together.

2. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots therein designated as first and second slots, and a horizontal slot extending between the vertical slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slots, a lock sleeve in the tubular body, a key on the mandrel, a cam surface on the key, said lock sleeve having a slot therein to receive said key, said slot being engageable by the cam surface on the key, a spring mounted in the tubular body below the lock sleeve and pressing against the bottom of said lock sleeve whereby the lock sleeve is pressed against said key to rotatably urge the mandrel in the tubular body and press said lugs and a side of the second vertical slots together.

3. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots therein designated as first and second slots, and a horizontal slot extending between the vertical slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slots, a lock sleeve in the tubular body below the mandrel, a key on the mandrel, said sleeve having a keyway therein into which said key may move, a cam surface on the key engageable by the lock sleeve to rotatably urge the mandrel in the tubular body and press said lugs and a side of the second vertical slots together, and spring means engaging the lock sleeve and urging the lock sleeve upwardly against said key.

4. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots therein designated as first and second slots, and a horizontal slot extending between the vertical slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slot, a lock sleeve in the tubular body, a key on the mandrel, a cam surface on the key, said key being engaged by the lock sleeve, means yieldably pressing the lock sleeve against the key to rotatably urge the mandrel in the tubular body and press said lugs and a side of the second vertical slots together, said lock sleeve having a cam slot therein, an inwardly projecting pin on the tubular body extending into said cam slot whereby said lock sleeve is rotated on downward movement thereof relative to said pin.

5. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slot, a lock sleeve in the tubular body below the mandrel, a key on the mandrel, a cam surface on the key, said sleeve having a keyway therein into which said key may move, said cam surface on the key being engageable by the lock sleeve to rotatably urge the mandrel in the tubular body and press said lugs and a side of the second vertical slots together, and spring means engaging the lock sleeve and urging the lock sleeve upwardly against said key, said lock sleeve having a cam slot therein, an inwardly projecting pin on the tubular body extending into said cam slot whereby said lock sleeve is rotated on downward movement thereof relative to said pin.

6. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots therein designated as first and second slots, and a horizontal slot extending between the vertical'slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slot, a lock sleeve in the tubular body below said mandrel, a key on the mandrel, an inclined cam surface on the lower end of said key, said inclined surface on the key being engaged by the lock sleeve to rotatably urge the key and the mandrel in the tubular body and press said lugs and a side of the second vertical slots together, means yieldably pressing the lock sleeve against the key, said lock sleeve having a vertical keyway therein to receive the key in one position thereof.

7. A safety joint comprising a mandrel, a tubular body, said tubular body being open at the top to receive said mandrel therein, coupling means on the lower end of the tubular body to receive a tool, coupling means on the upper end of the mandrel to receive drill pipe, said mandrel having pairs of adjacent vertical slots therein designated as first and second slots, and a horizontal slot extending between the vertical slots, said first slot being open at the lower end thereof, inwardly projecting lugs on the inside of said tubular body, said lugs being positioned in the first vertical slot and thence movable into the second vertical slot through said horizontal slot, a lock sleeve in the tubular body below said mandrel, a key on the mandrel, an inclined cam surface on the lower end of said key, said inclined surface on the key being engaged by the lock sleeve to rotatably urge the key and the mandrel in the tubular body and press said lugs and a side of the second vertical slots together, means yieldably pressing the lock sleeve against the key, said lock sleeve having a vertical keyway therein to receive the key in one position thereof, said lock sleeve having a cam slot therein, an inwardly projecting pin on the tubular body extending into the cam slot to rotatably urge the lock sleeve on vertical movement of said sleeve within the tubular body.

References Cited in the file of this patent UNITED STATES PATENTS 2,302,856 Hamon Nov. 24, 1942 2,327,503 Coberly Aug. 24, 1943 2,557,349 Howard June 19, 1951 2,708,100 Sutlifl May 10, 1955 

